This invention relates to vegetative trimmers of the type attached to a hand held power unit which utilize a high speed rotating filament or string as the cutting mechanism. The present invention comprises a universal fixed filament cutting head device for attachment to any variety of hand held power units.
There are currently known many types and styles of the filament trimmers or "weedeaters" as they are generically referred to. These trimmers basically fall into two main categories. One category consists of powered trimmers which have a spool of cutting filament contained within the cutting head and usually provide some means of automatically advancing the filament as the working ends are broken or splittered from use. The second category contains what would be called fixed line trimmers in which a predetermined length of filament is somehow retained in the cutting head and manually replaced when broken or otherwise used up.
Cutting heads which fit into category one above are described in U.S. Pat. Nos. 4,068,377 to Kimmel et al; 4,282,653 to Comer et ano.; 4,411,069 to Close; and 4,916,886 to Nakamura et ano. Trimmers of this type all provide for some method of automatic advancement of the filament medium as use dictates. Additionally, each of the above descibed cutting heads is made up of numerous parts and are usually specific for use on one type or brand of power unit. Furthermore, these type heads are subject to becoming jammed or clogged with grass or weed trimmings thereby adversely affecting their ease of operation.
Fixed element cutting heads which fall under category two above are described in U.S. Pat. Nos. 4,068,376 to Briar; 4,118,865 to Jaeymo et ano.; 4,571,831 to White; 4,685,279 to Gullett; and 4,756,146 to Rouse. These trimmers all use some sort of fixed length of fixed filament, and, in the case of the Jaeymo and Briar patents necessitate the use of a specifically shaped or specifically manufactured cutting elements. As in the category one cutting heads each of the above heads consist of multiple parts and are not universally adaptable to various power units. The complexity of the heads also increases the cost of manufacture of these units.
The present invention is intended to meet all of the shortcomings of the above described art. It is a one piece universally adaptable cutting head which can be manufactured and easily configured to fit virtually any power unit. It allows for the use of various diameters of cutting filament which can be used from a standard bulk spool. The filament can be replaced in seconds without any disassembly or removal of the cutting head from the unit and multiple filaments adapted for a particular usage can be used. Further, the configuration and construction provide for a well balanced durable tool.